Publications Internationales
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Item Green synthesis, antioxidant and antibacterial activities of 4-aryl-3,4- dihydropyrimidinones/thiones derivatives of curcumin. Theoretical calculations and mechanism study(Elsevier, 2019) Khaldi-Khellafi, Nassima; Makhloufi-Chebli, Malika; Oukacha-Hikem, Djamila; Terachet Bouaziz, Souhila; Ould Lamara, Kamilia; Idir, Taous; Benazzouz-Touami, Amina; Dumas, Françoise3,4-Dihydropyrimidin-2(1H)-one/thione analogs of curcumin were synthesized in good yield by a onepot multi-component cyclocondensation using curcumin, substituted aromatic aldehydes, and urea/ thiourea in less volume of ethanol catalysed by commercial heteropolyacide Keggin type H3PMo12O40 5% mol as a recyclable and nontoxic catalyst under conventional heating and microwave irradiation. All the synthesized curcumin derivatives 4aen were screened for antioxidant and antimicrobial activity. Biological activity data of the synthesized showed that most of the synthesized compounds exhibited greater antioxidant and antibacterial activity than curcumin. Geometries of synthesized compounds were optimized by using B3LYP method with 6-31G* basis set. Then, DFT based reactivity descriptors such as HOMO, LUMO, chemical hardness, electronegativity, chemical potential were calculated and discussed.Item Numerical simulation and experimental analysis of magneto-mechanical behavior of anti-seismic active sandwich structure(Extrica, 2019) Zerrouni, Nassim; Aguib, Salah; Grine, Ali; Chikh, NoureddineThis work focuses on the quasi-static behavior study for simply supported sandwich beams with aluminum faces and magnetorheological elastomer core subjected to three points bending subjected to a magneto-mechanical loading by numerical and experimental investigations. The mechanical properties of the magnetorheological elastomer core are measured experimentally and the mechanical behavior of the MRE was identified by the generalized Maxwell rheological model. Depending upon the adjustable properties of the beam, energy dissipation is by core shear. A systematic series of experiments and finite elements simulations have been performed in order to assess the static behavior of the beam. The results obtained show a significant influence of the magnetic field intensity on the flexural displacement of the beam.Item Life cycle assessment application for the medical waste management in Algeria(2019) Kihal, Nafika; Tairi, AbdelazizOur study aimed to assess environmental im-pacts of a medical waste (MW) management sys-tem in using life cycle assessment (LCA) methodol-ogy in Algeria. We use standardized CML2 method to ana-lyze the environmental impacts resulting from one scenario’s MW management system for One kilo-gram of MIW disposed, including: production raw material of the MW, transportation, MW incinera-tion and MW ash storage. Seven impacts categories were taken into ac-count: Abiotic depletion (AD), Acidification, Eu-trophication, Global warming (GWP100), Ozone layer depletion (ODP), Human toxicity (HT) and Fresh water aquatic ecotoxicity (FAET). The data was obtained from Bachir Montouri hospital, the ECFERAL company, ecoinvent data-base and the literatures. Our study showed that all impact categories had significant values, except for ODP. The MW-Transportation contributed to the majority of im-pacts category. The highest impact category of the MW process was the eutrophication about 51% resultant of the fiber cotton production (38%). Despite significant emissions of dioxins, the BTEX and heavy metals which contributed for both HT and FAET impact, the MW incineration process contributed the least for AD, acidification, eutroph-ication, GWP100 after the MW ash storage. Our findings provide a useful tool to guide pol-icymakers in their choice of environmental perfor-mance indicators for disposal of MW.Item Effect of shape factor on structural reliability analysis of a surface cracked pipeline-parametric study(2019) Guillal, Abdelkader; Abdelbaki, Noureddine; Bensghier, Mohamed El Amine; Betayeb, Mourad; Kopei, BogdanThe variation of crack shape factor (a/c) during propagation has an important role on calculation of the stress intensity factor (SIF), where imprecise estimation of this latter can lead us to an inaccurate prediction of failure probabilities. For the case of external cracked surface pipeline carried oil and gas products, such estimation can results undesired fault decisions like excessive repairs action or inspection planning. In this paper, the structural integrity analysis of pipeline with semi elliptical crack on the external surface is evaluated. Reliability calculations expressed in term of reliability index β are carried out based on Monte Carlo simulation and First Order reliability Method (FORM). The crack shape factors are varied to cover a variety of geometries from shallow to deep cracks while fatigue crack growth is assumed in depth direction. For SIF estimation, surface and deep point are considered. Results of the analysis indicate that for a constant crack depth a/t, the reliability index is strongly affected by a/c ratio and the trend is not similar in deep and surface point for different crack shapes.Item A comparative study between convolutional and multilayer perceptron neural networks classification models(2019) Bachiri, Mohamed Elssaleh; Harrar, KhaledImage classification plays an important role in image processing, computer vision, and machine learning. This paper deals with image classification using deep learning. For this, a conventional neural network (CNN) and multilayer perceptron neural network (MLP) models were used for the classification. The two models were implemented on the MNIST dataset which was used at 100% and half of capacity, The models were trained with fixed and flexible number of epochs in two runs. CNN provided an accuracy of 98,43% with a loss of 4,44%, where MLP reached 92,80% of classification with a loss of 25,87%. Indeed, for each model, variables as number of filters, size, and activation functions were discussed. The CNN demonstrated a good performance providing high accuracy for image and also proved to be a better candidate for data applications.Item The effect of atmospheric optical phenomena photographed by students on learning motivation(2018) Blizak, Meriem Djanette; Remli, S.; Blizak, SalahThe atmospheric optical phenomena (mirages, rainbows, halos, blue sky, sunset …) that we can observe in everyday life are very interesting for stimulating the students’ curiosity. This study aimed to investigate the effect of atmospheric optical phenomena photographed by university students’ on their learning motivation in geometrical optics (GO). To achieve the aim of the study, an available sample of the study composed of (200) students from the biology department of Boumerdes University, Algeria, was used. The subjects were randomly distributed into two groups: (165) of them in the experimental group and (35) in the control group. We have asked every student in the experimental group to use their smartphone or tablet to taking photos of an atmospheric optical phenomena and giving a physical explain. According to the motivation post and pres test, there were statistical significant differences in learning motivation in the favor of the experimental groupItem The effect of using the history of sciences on conceptual understanding and intrinsic motivation(2017) Blizak, Meriem DjanetteThis study investigates the effect of using the history of science in teaching geometrical optics on the motivation and conceptual understanding of first year university students. For this purpose, 54 students were randomly selected, then divided into two groups: the experimental group was taught by using history of science before traditional geometrical optics teaching, and the control group was taught by traditional method only. Data were collected using two instruments: Geometrical Optics Understanding Concept Test and Geometrical Optics Intrinsic Motivation Scale. The finding showed that before instruction, the students have important and prevalent misconceptions about vision, propagation of light and refraction. After teaching of geometrical optics, the study shows that using the history of science shows greater effect on intrinsic motivation and concept understanding. The results have some implications for teaching physics, especially when the traditional teaching is inevitableItem What thinks the university's students about propagation of light in the vacuum?(2013) Blizak, Meriem Djanette; Chafiqi, Fouad; Kendil, DjamelThis study aims to study the conceptions of university students related to the notion of propagation of light in a vacuum. In order to fulfill our aim, a case study research method was used in the study, whose sample consisted of 321 Algerian undergraduates in different levels at science faculty (before and after the optics courses). The data were collected through a test comprising three questions. The results have indicated two students’ misconceptions concerning propagation of light in vacuum. The first one is that the light does not propagate in a vacuum. The second is that the light propagates according the horizontal direction (new misconception). The possible origins of these misconceptions are discussed and suggestions for how to prevent them are given. Also, our results suggest that university students who had a higher level of physics knowledge than their counterparts who studied only geometrical optics, they still held of the same misconceptions. Formal or traditional teaching seems helpless to facing these misconceptionsItem Determination of university students’ misconceptions about light using concept maps(Elsevier, 2014) Blizak, Meriem Djanette; Chafiqi, FouadThe concept map has evolved, in recent years, as an important teaching and learning tool. It engages students in active learning and assists instructors with their delivery. Thus, we believe that it has the power to be relevant and effective to reflect the design of a poly-functional teaching tool. We argue in favor of renewing didactic tools used in education, in general, and in teaching GO (geometric optics) in particular. The main purpose of this study, however, is to show that the concept mapping is a very effective way in terms of revealing the misconceptions of students, studying GO, during their university year. 52 freshman students (first year) majoring in life science and nature (LSN) were asked to draw a conceptual map about propagation of light; a two-stage experiment: before and after formal teaching sessions. The findings of the qualitative analysis of the students’ maps are in line with the results of other research; students have many misconceptions about light and traditional strategy used for teaching GO is not effective for conceptual change. Also, The approach of scoring tasks, as only one survey is not recommended